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Investigations of the freshwater isopod genus Lirceus Rafinesque, 1820 in Ohio and Kentucky USA reveal surprising results regarding the taxon- omy of the genus. Given the incomplete states of their original descriptions, Lirceus fontinalis Rafinesque, 1820 and Lirceus richardsonae Hubricht & Mackin, 1949 were subjected to molecular and morphological analyses and then redescribed from as geographically near to their type locali- ties as possible. The range of L. fontinalis is circumscribed to include sites now only in Fayette County, Kentucky, while the range of L. richardsonae is expanded to include much of western Ohio. In addition, a new species from Delaware County, Ohio was identified and is described. This unexpected species showed relatively little affinity to L. fontinalis/richardsonae and may represent a species from a different faunal assemblage. The presence of these two isopod lineages suggests a contact zone in Ohio due to postglacial dispersal from the east and from the south. 

We describe a new species of subterranean amphipod (Amphipoda: Crangonyctidae) in the genusStygobromusfrom a hypotelminorheic seepage spring at Shepherd Parkway, part of National Capital East Parks, Washington, D.C., USA, part of the National Park System, using both morphological and genetic approaches. The Anacostia Groundwater Amphipod,S. anacostensissp. nov.is a member of theS. tenuisspecies group but differs from related congeners based on body size, serrate blade-like edge of both palms of gnathopods 1 and 2, presence of rastellate setae on the posterodistal margin of the carpus of gnathopod 2, and aspects of the second antennae, mandibular palp, pereopods 5–7, uropods 1 and 2, and telson. Moreover,S. anacostensissp. nov.is genetically distinct fromS. tenuisin the Washington D.C. metropolitan area. The description ofS. anacostensissp. nov.increases the number of describedStygobromusspecies to eight in the Washington D.C. area and highlights the need for continued biodiversity studies, even in regions that have received considerable attention.